in imageCopier/src/main/scala/com/gu/imageCopier/attempt/Attempt.scala [103:110]
def traverseOption[A, B](
a: Option[A]
)(f: A => Attempt[B])(implicit ec: ExecutionContext): Attempt[Option[B]] = {
a match {
case None => Attempt.Right(None)
case Some(a) => f(a).map(Some.apply)
}
}